Thickened hydrochloric acid cleaner compositions are known in the art. For example, U.S. Pat. Nos. 3,793,221 and 3,832,234, both to Otrhalek, et al., disclose compositions containing an aqueous hydrochloric acid, an organic acid, a nonionic surfactant, an anionic surfactant, and water, the particular combinations of surfactants disclosed in the Otrhalek, et al., patents exhibiting unusual thickening properties. U.S. Pat. No. 4,302,253 to Ciullo discloses storage stable liquid cleaning compositions for use on porcelain-type surfaces, which compositions comprise an aqueous mineral acid solution thickened with smectite clay and xanthan gum. A stabilizing amount of 1-hydroxy-ethyl-2-amidoimidazoline is included in the compositions of Ciullo so that they retain their initial viscosity during their shelf life. U.S. Pat. No. 3,681,141 to Muoio concerns a process for cleaning hard surfaces such as porcelain and enamel surfaces by applying to such surfaces a viscous, fluid composition consisting essentially of water, a mineral acid, and a water-soluble synthetic organic polymer, e.g., polymers selected from the group consisting of polyvinyl alcohol and polyethylene glycol. U.S. Pat. No. 4,561,993 to Choy, et al., discloses a thixotropic acid-abrasive cleaner comprising about 6 to 12% precipitated silica; about 0.05 to 2.5% cationic, nonionic, or zwitterionic or amphoteric surfactant, or mixtures thereof, the surfactant having hydrogen bonding ability; an acid, and an abrasive. Viscosities obtained are typically quite high, in the order of 4,000-20,000 centipoise. An exemplary cationic surfactant disclosed in Choy, et al., is dialkyl dimethyl ammonium chloride, which desirably has disinfectant properties. Brit. Pat. No. 1,443,244 to Reckitt and Colman concerns an acid cleaning composition containing hydrochloric acid; a second acid such as phosphoric acid; a thickener; acid stable detergents, and water. The thickening agent incorporated in the Brit. Pat. No. 1,443,244 compositions is an ethoxylated or propoxylated tertiary amine of the formula ##STR1## wherein R is an alkyl or alkenyl derived from a fatty acid or an alkaryl having 8 to 12 carbons in the alkyl; A is ethoxy or propoxy, and x and y are integers of from 1 to 3. A quaternary ammonium compound such as benzyldodecyltrimethyl ammonium chloride may be incorporated as a bacetericide. U.S. Pat. No. 4,396,525 to Rubin, et al., discloses an acid-free aqueous liquid scouring composition containing an anionic surfactant and an alkylamido betaine as a cosurfactant, the Rubin, et al., compositions having satisfactory storage stability as indicated at column 6, Table 3. The betaine constituent of Rubin, et al, is a replacement for nonionic cosurfactants of the prior art, that is alkanolamines, amine oxides, and ethoxylated fatty alcohols. Technical Data Sheet: Varion TEG 2, Sherex Chemical Company, Inc. (1984) discloses Varion TEG, a 41-44% active solution of dihydroxyethyl tallow glycinate as a thickener for hydrochloric acid/phosphoric acid solutions, alone or in combination with Varonic T-202, a polyethylene glycol amine of hydrogenated tallow having an average of 2 moles ethylene glycol per molecule.
Cleaner compositions to be used in the cleaning of porcelain and other such surfaces advantageously should include a bactericidal amount of a quaternary ammonium compound having as a substituent group a benzyl radical. Inclusion of such beneficial bactericides in thickened hydochloric acid compositions has been found to have a destabilizing effect on the compositions at the higher temperature that would be encountered during summer warehouse storage.
In investigating this problem, it was found, quite surprisingly, that certain cosurfactants selected from the group consisting of alkyl betaines; alkoxylated tertiary amines; ethoxylated nonyl phenols, and phosphate esters of amine oxides substantially improve the thermal stability of thickened hydrochloric acid compositions containing the aforementioned quaternary compound.
Accordingly, it is an object of this invention to provide an aqueous, thickened composition containing hydrochloric acid and a quaternary benzyl ammonium compound.
It is a primary object of the present invention for such compositions to exhibit good storage stability at elevated temperatures.
These and other objects, advantages, and benefits of the present invention will be more fully understood by reference to the complete specification provided herein.